PF_RING is an option but it requires a kernel module and specific network cards. Before then, the memory map sniffing feature of the Linux kernel [1] can improve libpcap performance. Not quite to 10G speeds, though, but I think enough for most cases :-)
Any plans to support it? Part of my job (historically) has been building line rate pcap appliances that do pcaps at nanosecond resolution (using endace cards, Mellanox, or solarflare). PF_RING is a bit tricky to get working, but is completely flawless when you get it running.
This software looks fantastic however.